Hi . If your masks fits well now and you are sleeping comfortably, you should see a change in your fatigue levels within a day or two. Is it possible there are other factors at play? My husband got some relief when he began using a CPAP, but he still struggled to stay awake, especially in the early evening. His primary care doctor tested for nutrional deficiencies and found he was extremely low on Vitamin D, despite the fact that he spent a lot of time in the sun. HIs fatigue levels improved dramatically with supplements. My oldest son also had issues with debilitating fatigue and learned he lacked Vitamin B12. Supplements did the trick. It might be worth investigating. Warm wishes. - Lori (Team Member)